Re: Regex Match() Abortion

From: eydelber (eydelber_at_[hidden])
Date: 2002-12-04 17:56:37

Well, you are absolutely right.  The weird thing is that I tried to 
catch exceptions within my execute method, but for some reason it 
wasn't catching anything; however, now that I tried the stripped 
down code that I replied with to John Maddock, and added a catch, I 
get the error that you also found.

Now that my problem has finally been isolated, do you know what this 
exception means?  I didn't think that the regex was that 
complicated, and it works fine for other regex's that are very 
similar.  What specifically is search depth?

Also, following up on your introduction to your answer, can you 
expand on the problems you had compiling, and any general problems 
you found with my code?  I am only 18, and I've just started getting 
into C++, so I am trying to learn as much as possible from people 
who know what they are talking about.  It is obvious that I have 
made many mistakes, as you point out, so any expansion on these 
would be extremely helpful. I am running GCC 2.96 with -Wall, and I 
didn't have any warnings or errors compiling, so how did you have so 
many problems with GCC 3.2? It doesn't seem too backwards-
compatabile if I am not having problems and you are.

A few questions on only the comments that you included:

2: Where did you have to include <iostream>?
3: Again, where did you have to add using directives?
4: Do default values only have to be in the declaration?
5: Can you expand further on these unmentioned warnings?

Thank you VERY much for all your help, I learn something new 
everyday.

Kevin

--- In Boost-Users_at_y..., Stephen Jackson <stephen.jackson_at_s...> 
wrote:
> eydelber wrote:
> > 
> > Code is here:
> > 
> > http://www.myplaceonline.com/code/code.htm
> > 
> > Just compile everything together and run ./try.cgi, and from 
there 
> > enter an sql string similar to (you'll also have to create a 
table 
> > first like this: "create table test (one int)"):
> > 
> > insert into test 
(lkfsdjlkafdjklfsdajflkjfdklsjfsdlkjsfldkjfskldaj) 
> > values (1);
> > 
> 
> With some difficulty, I have reproduced your problem with GCC 3.2 
on Red 
> Hat 8.0.
> 
> The difficulties were mainly non-conforming code:
> 	1. Get James Clark's expat parser.
> 	2. Include <iostream> where necessary.
> 	3. Add further using directives where necessary.
> 	4. Remove the non-conforming duplication of default 
parameter values in 
> the headers and the implementation files.
> 	5. There are further warnings which matter but are 
irrelevant to this 
> exercise.
> 
> In the general case, if a C++ program compiled with GCC 
prints "Aborted" 
> and exits, this is caused by an unhandled exception.
> 
> In this case, you promise that textdb::TextDB::execute will only 
throw 
> TextDBException. However, RegEx::Match is thowing a different 
exception. 
> You are not handling this exception in textdb::TextDB::execute, 
and you 
> have promised not to leak it; the result is that GCC causes your 
program 
> to abort.
> 
> By removing the throw specification from your function and adding 
extra 
> catches in main(), I can tell you that RegEx::Match is throwing an 
> exception whose what() reports "Max regex search depth exceeded."
> 
> I hope this helps.
> 
> Regards,
> 
> Stephen Jackson
> -- 
> stephen.jackson_at_s...       http://www.scribitur.com/spj/